Presentation on theme: "Astronomy Chapter 2 The Solar System"— Presentation transcript:
1Astronomy Chapter 2 The Solar System Observing the Solar SystemSection 1
2VocabularyGeocentric: A description of the solar system in which all of the planets revolve around EarthEllipse: An elongated circle, or oval shape; the shape of the planets’ orbitsHeliocentric: A description of the solar system in which all of the planets revolve around the sunIntertia: the tendency of a moving object to continue in a straight line or a stationary object to remain in place
3Main IdeasPtolemy thought that Earth is at the center of the system of planetsCopernicus thought that the sun is at the center of the planets. Galileo’s observations supported Copernicus’s theory.Kepler discovered that the orbits of the planets are ellipsesNewton concluded that two factors—inertia and gravity—combine to keep the planets in orbit
4Guiding QuestionsHow is Copernicus’s description of the system of planets different from Ptolemy’s description?How did Galileo’s observations of Jupiter’s moons help to show that the geocentric explanation is incorrect?What shape are the orbits of the planets? How was the discovery of this orbit shape made?What two factors act together to keep the planets in orbit around the sun?
6VocabularyNuclear fusion: the process by which hydrogen atoms join together to form helium, releasing energyCore: the central part of the sun, where nuclear fusion occursPhotosphere: the inner layer of he sun’s atmosphereChromosphere: the middle layer of the sun’s atmosphereCorona: the outer layer of the sun’s atmosphere
7VocabularySolar wind: a stream of electrically charged particles produced by the sun’s coronaSunspot: A dark area of gas on the sun that is cooler than surrounding gasesProminence: a loop of gas that protrudes from the sun’s surface, linking parts of sunspot regionsSolar flare: an explosion of hydrogen gas from the sun’s surface that occurs when lops in sunspot regions suddenly connect
8Main Ideas The sun’s energy comes from nuclear fusion The sun’s atmosphere has three layers: the photosphere, the chromosphere, and the coronaFeatures on or above the sun’s surface include sunspots, prominences, and solar flares
9Guiding Questions How is energy produced in the sun’s core? Name the layers of the sun’s atmosphere.What is the solar wind?Describe three features found on or above the surface of the sun.Why do sunspots look darker than the rest of the sun’s photosphere?How does the number of sunspots change over time?
11VocabularyTerrestrial planets: the name given to the four inner planets, Mercury, Venus, Earth, and MarsRetrograde rotation: The spinning motion of a planet from east to west, opposite to the rotation of most planets and moonsGreenhouse effect: the trapping of heat by a planet’s atmosphere
12Main IdeasThe four inner planets—Mercury, Venus, Earth, and Mars—are small and have rocky surfaces. They are often called the terrestrial planets
13Guiding QuestionsWhat features do all of the inner planets have in common?What is Mercury’s atmosphere like? ExplainWhy can astronomers see the surface of Mars clearly, but not the surface of Venus?How have astronomers been able to study the surface of Venus?What evidence do astrnomomers have that water once flowed on Mars?
15VocabularyGas Giant: the name given to the first four outer planets: Jupiter, Saturn, Uranus, and Neptune
16Main IdeasFour outer planets—Jupiter, Saturn, Uranus, and Neptune—are much larger than EarthPluto and Charon have solid surfaces and masses much less than that of Earth
17Guiding QuestionsHow are the gas giants similar to each other? How are they different?How is Pluto different from the gas giants?What is the most prominent feature of Jupiter’s surface? What cuases this feature?Why do astrnomoers think Uranus may have been hit by another object billions of years ago?
19VocabularyComet a ball of ice and dust whose orbit is a long narrow ellipseAsteroid: objects revolving around the sun that are too small and too numerous to be considered planetsAsteroid belt: the region of the solar system between the orbits of Mars and Jupiter, where many asteroids are foundMeteoroid: a chunk of rock or dust in spaceMeteor: a streak of light in the sky produced by the burning of a meteoroid in Earth’s atmosphereMeteorites: a meteoroid that has hit Earth’s surface
20Main IdeasComets are chunks of ice and dust that usually have long, elliptical orbitsMost asteroids revolve around the sun between the orbits of Mars and Jupiter
21Guiding Questions What is a comet made of? Where are most asteroids found?What are the main sources of meteoroids?What is the difference between a meteor and a meteorite?
23VocabluarlyExtraterrestrial Life: life that arises outside of Earth
24Main IdeasEarth has liquid water and a suitable temperature range and atmosphere for living things to survive.Since life as we know it requires water, scientists hypothesize that mars may have once had the conditions for life to exist
25Guiding Questions What conditions does life on Earth need to survive? Why do astronomers think there could be life on Europa?How did the Viking missions search fro life on Mars?